There were today questions over how Liberian government worker Mr Sawyer was let on flights while clearly showing symptoms of Ebola – which has killed 672 people in Liberia, Guinea and Sierra Leone since it broke out in February.

Experts from Public Health England have met UK Border Agency officials to make sure staff are aware of the signs to look for in Ebola sufferers.

PHE has also used its national medical alert system to advise all UK doctors to “remain vigilant for unexplained illness in those who have visited the affected area”.